Stereoscopic Microscope
Definition
Two separate light paths producing a true 3D image at low magnification (typically 7x to 40x). Used for trace recovery, gross examination of documents and insects.
- Magnification range
- Typically 7x to 40x
- Optical design
- Two separate light paths, true 3D image
- Applications
- Trace recovery, document examination, insect examination
Common questions
How does a stereoscopic microscope differ from a comparison microscope in casework use?+
A stereoscopic microscope gives one examiner a single 3D view of a specimen for gross examination and recovery, while a comparison microscope joins two separate optical paths into one split field so two specimens, such as two bullets, can be viewed side by side for direct comparison.
Why is a stereoscopic microscope commonly the first tool used on a questioned document?+
Its low power and true depth of field let an examiner scan ink strokes, paper fibres, and indented writing for surface anomalies before committing the document to more destructive or specialised instrumental analysis.
Related terms
- Comparison Microscope
- Two compound microscope bodies connected by an optical bridge that presents one half of each body's image in a single split eyepiece...
- Depth of Field
- Axial thickness of the specimen that appears acceptably in focus at one time. High in stereoscopic microscopes, very low in oil-immersion compound...
- EDX / EDXRF
- Energy-dispersive X-ray detector attached to an SEM. Identifies elements from characteristic X-rays emitted when the beam strikes the sample. Backbone of GSR...
- Fluorescence Microscope
- Uses UV or short-wavelength excitation to make fluorophores emit longer-wavelength light. Used for semen, saliva, fibres and ink discrimination.
- Numerical Aperture (NA)
- The product of the refractive index of the medium between objective and specimen and the sine of the half-angle of the maximum...
- Polarising Microscope
- Compound microscope fitted with a polariser below and an analyser above the stage. Used to study birefringent materials like fibres, minerals and...
- Resolution
- The ability of a mass analyser to distinguish two ions of nearly equal m/z, defined as m/Δm at a given peak. A...
- SEM
- Scanning electron microscope. Focused electron beam raster-scans the sample surface; resolution down to a few nanometres with great depth of field. Paired...
- TEM
- Transmission electron microscope. Electrons pass through an ultra-thin section; resolution below 1 nm. Rare in routine forensic casework, common in research.